Comprehensive Electrothermal Characterization Analysis for Scaled Nanochannels in Gate-All-Around Field-Effect Transistors

Gate-all-around field-effect transistors (GAAFETs) have garnered extensive research interest and industrial attention due to the higher gate control capability and remarkable scalability. However, as the nanochannel scales down, the phonon-boundary scattering inside channels is dramatically strengthened, resulting in a significant decrease in phonon mean free path (MFP), which in turn leads to a decrease in thermal conductivity and deteriorates electrothermal characteristics. In this paper, to accurately evaluate the degradation of thermal conductivity for confined nanochannels, an analytical model is developed by revising the boundary-induced reduction function related to both nanochannel width and thickness. The results show that the thermal conductivity calculated by the proposed model agrees well with the experimental data within 1% error over large temperature range for nanosheet and nanowire structures. Moreover, significant deviations of 6.11% in on-state current and 41.7 K in temperature are observed between the proposed and conventional models for three-stacked GAAFETs. The proposed revised methodology offers invaluable insights for assessing the electrothermal characteristics of nanodevices.